Turbomachine airfoil

ABSTRACT

A turbomachine airfoil includes a base portion and a blade portion extending from the base portion to a tip portion defining a radial span dimension. The blade portion includes a leading edge, a trailing edge, a pressure side and a suction side. An axial chord dimension is defined between the leading edge and the trailing edge. At least one protuberance is provided on the pressure side. The at least one protuberance extends from about 10% of the axial chord dimension to about 90% of the axial chord dimension.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to the art of turbomachinesand, more particularly, to a turbomachine airfoil.

Turbomachines typically include a compressor portion and a turbineportion. The compressor portion forms a compressed airstream that isintroduced into the turbine portion. In a gas turbomachine, a portion ofthe compressed airstream mixes with products of combustion forming a hotgas stream that is introduced into the turbine portion through atransition piece. In a steam turbomachine, the hot gas stream may takethe form of a high pressure steam flow. The hot gas stream expandsthrough the turbine portion along a hot gas path.

The hot gas stream impacts turbomachine airfoils arranged in sequentialstages along the hot gas path. The airfoils are generally connected to awheel which, in turn, may be connected to a rotor. Typically, the rotoris operatively connected to a load. The hot gas stream imparts a forceto the airfoils causing rotation. The rotation is transferred to therotor. Thus, the turbine portion converts thermal energy from the hotgas stream into mechanical/rotational energy that is used to drive theload. The load may take on a variety of forms including a generator, apump, an aircraft, a locomotive or the like.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of an exemplary embodiment, a turbomachineairfoil includes a base portion and a blade portion extending from thebase portion to a tip portion defining a radial span dimension. Theblade portion includes a leading edge, a trailing edge, a pressure sideand a suction side. An axial chord dimension is defined between theleading edge and the trailing edge. At least one protuberance isprovided on the pressure side. The at least one protuberance extendsfrom about 10% of the axial chord dimension to about 90% of the axialchord dimension.

According to another aspect of an exemplary embodiment, a turbomachineincludes a compressor portion, and a turbine portion operativelyconnected to the compressor portion. A turbomachine airfoil is arrangedin one of the compressor portion and the turbine portion. Theturbomachine airfoil includes a base portion and a blade portionextending from the base portion to a tip portion defining a radial spandimension. The blade portion includes a leading edge, a trailing edge, apressure side and a suction side. An axial chord dimension is definedbetween the leading edge and the trailing edge. At least oneprotuberance is provided on the pressure side. The at least oneprotuberance extends from about 10% of the axial chord dimension toabout 90% of the axial chord dimension.

According to yet another aspect of an exemplary embodiment, a method offorming a turbomachine airfoil includes forming a base portion and ablade portion, and creating at least one protuberance on a pressure sideof the blade portion. The at least one protuberance extends from about10% of an axial chord dimension to about 90% of the axial chorddimension of the blade portion.

These and other advantages and features will become more apparent fromthe following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF DRAWINGS

The subject matter, which is regarded as the invention, is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features, and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 is a partial perspective view of a turbomachine airfoil, inaccordance with an exemplary embodiment;

FIG. 2 is a schematic representation of a turbomachine including aturbomachine airfoil, in accordance with an exemplary embodiment;

FIG. 3 is a pressure side view of the turbomachine airfoil of, inaccordance with another aspect of an exemplary embodiment;

FIG. 4 is a top view of the turbomachine airfoil of FIG. 3;

FIG. 5 is a pressure side view of a turbomachine airfoil, in accordancewith another aspect of an exemplary embodiment; and

FIG. 6 is a pressure side view of a turbomachine airfoil, in accordancewith yet another aspect of an exemplary embodiment.

The detailed description explains embodiments of the invention, togetherwith advantages and features, by way of example with reference to thedrawings.

DETAILED DESCRIPTION OF THE INVENTION

A turbomachine system, in accordance with an exemplary embodiment, isindicated generally at 2, in FIG. 2. Turbomachine system 2 includes aturbomachine 4 having a compressor portion 6 operatively connected to aturbine portion 8 through a shaft 10. Compressor portion 6 is alsofluidically connected to turbine portion 8 via a combustor assembly 12including at least one combustor 14. Turbomachine system 2 is also shownto include an air inlet system 18 that delivers an airflow to an inlet(not separately labeled) of compressor portion 6. Air inlet system 18may condition the airflow prior to introduction into compressor portion6. Turbomachine system 2 is further shown to include a driven component20 operatively connected to turbine portion 8. Driven component 20 maytake the form of a generator, a pump or other mechanical load. Turbineportion 8 is still further shown to include a plurality of buckets 30rotatably mounted within a housing (not separately labeled). Buckets 30are arranged in a number of stages extending along a hot gas path (notseparately labeled) of turbine portion 8.

Air enters air inlet system 18 and flows to compressor portion 6. Theair is compressed and passed to combustor assembly 12. A portion of theair is passed into turbine portion 8 for cooling. In combustor assembly12, the air is mixed with a fuel and or diluents to form a combustiblemixture. The combustible mixture is combusted forming hot gases thatpass from combustor assembly 12 to turbine portion 8 via a transitionpiece (not shown). The hot gases expand through turbine portion 8 atwhich time buckets 30 convert thermal energy into mechanical energy thatdrives driven component 20. The hot gases may pass from turbine portion8 toward an exhaust system (also not shown).

Reference will now follow to FIGS. 1 and 3 in describing a turbomachineairfoil or bucket 40 that may be included in plurality of buckets 30.Turbomachine airfoil 40 may be arranged in any one of the plurality ofstages (not separately labeled) of turbine portion 8. Turbomachineairfoil 40 includes a base portion 42 that may be operatively coupled toa rotor wheel (not shown) in turbine portion 8 and an airfoil portion44. Airfoil portion 44 extends from a first or base end portion 48 to asecond or tip end portion 50. Base end portion 48 is formed with, andextends radially outwardly of, base portion 42. Turbomachine airfoil 40includes an airfoil surface 52 having a suction side 54 and a pressureside 56. Airfoil surface 52 also includes a leading or upstream edge 59and a trailing or downstream edge 60. Airfoil portion 44 includes anaxial chord dimension 65 defined between leading edge 59 and trailingedge 60 and a radial span dimension 67 defined between base end portion48 and tip end portion 50.

In accordance with an exemplary embodiment, airfoil portion 44 includesa protuberance 74. In accordance with an aspect of an exemplaryembodiment, protuberance 74 is arranged on pressure side 56 of airfoilportion 44. In further accordance with an exemplary embodiment,protuberance 74 extends from about 10% of axial chord dimension 65 toabout 90% of axial chord dimension 65. In accordance with another aspectof an exemplary embodiment, protuberance 74 extends from about 20% ofaxial chord dimension 65 to about 80% of axial chord dimension 65. Instill further accordance with an aspect of the exemplary embodiment,protuberance 74 extends from about 5% of radial span dimension 67 toabout 100% of radial span dimension 67. In accordance with yet stillanother aspect of an exemplary embodiment, protuberance 74 extends fromabout 50% of radial span dimension 67 to about 95% of radial spandimension 67. Protuberance 74 may also extend from about 50% of radialspan dimension 67 to about 90% of radial span dimension 67.

FIG. 4, wherein like reference numbers represent corresponding parts inthe respective views, illustrates a protuberance 84 extending betweenabout 25% of axial chord length 65 to about 75% of axial chord length65. FIG. 5, wherein like reference numbers represent corresponding partsin the respective views, illustrates a plurality of protuberances 90extending between about 10% of axial chord dimension 65 to about 90% ofaxial chord dimension 65 and between about 5% of radial span dimension67 to about 100% of radial span dimension 67. FIG. 6 wherein likereference numbers represent corresponding parts in the respective viewsillustrates a plurality of protruberances 100 extending across radialspan dimension 67 from about 5% of radial span dimension 67 to about 90%of radial span dimension 67.

At this point it should be understood that the exemplary embodimentsdescribe a turbomachine airfoil having a protuberance extending betweenan axial chord length and a radial span length of an airfoil surface.The shape of the protuberance may vary and could include humps, bumps,ridges, and the like. Further, the number and location of theprotuberances may vary. The protuberance(s) form a conditioning zone onthe turbomachine airfoil. The conditioning zone enhances aeromechanicsand/or aeroelastics of the blade. For example, the protuberance(s) mayimprove blade stability allowing for longer airfoils that would notrequire a part span shroud. Various protuberances have been shown tosignificantly increase bucket stability. In addition, the protuberanceenables frequency tuning of the bucket to avoid resonant mode excitationwhile, at the same time, reducing or maintaining rotating pull load.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

What is claimed is:
 1. A turbomachine airfoil comprising: a baseportion; a blade portion extending from the base portion to a tipportion defining an radial span dimension, the blade portion including aleading edge, a trailing edge, a pressure side and a suction side, anaxial chord dimension being defined between the leading edge and thetrailing edge; and at least one protuberance provided on the pressureside, the at least one protuberance extending from about 10% of theaxial chord dimension to about 90% of the axial chord dimension.
 2. Theturbomachine airfoil according to claim 1, wherein the at least oneprotuberance extends from about 25% of the axial chord dimension toabout 75% of the axial chord dimension.
 3. The turbomachine airfoilaccording to claim 1, wherein the at least one protuberance includes aplurality of protuberances extending across the axial chord dimension.4. The turbomachine airfoil according to claim 1, wherein the at leastone protuberance includes a plurality of protuberances extending acrossthe radial span dimension.
 5. The turbomachine airfoil according toclaim 1, wherein the at least one protuberance extends from about 5% ofthe radial span dimension to about 100% of the radial span dimension. 6.The turbomachine airfoil according to claim 5, wherein the at least oneprotuberance extends from about 50% of the radial span dimension toabout 95% of the radial span dimension.
 7. The turbomachine airfoilaccording to claim 6, wherein the at least one protuberance extends fromabout 50% of the radial span dimension to about 90% of the radial spandimension.
 8. The turbomachine airfoil according to claim 1, wherein theturbomachine airfoil comprises a turbine bucket.
 9. A turbomachinecomprising: a compressor portion; a turbine portion operativelyconnected to the compressor portion; and a turbomachine airfoil arrangedin one of the compressor portion and the turbine portion, theturbomachine airfoil including a base portion; a blade portion extendingfrom the base portion to a tip portion defining a radial span dimension,the blade portion including a leading edge, a trailing edge, a pressureside and a suction side, an axial chord dimension being defined betweenthe leading edge and the trailing edge; and at least one protuberanceprovided on the pressure side, the at least one protuberance extendingfrom about 10% of the axial chord dimension to about 90% of the axialchord dimension.
 10. The turbomachine according to claim 9, wherein theat least one protuberance extends from about 25% of the axial chorddimension to about 75% of the axial chord dimension.
 11. Theturbomachine according to claim 9, wherein the at least one protuberanceincludes a plurality of protuberances extending across the axial chorddimension.
 12. The turbomachine according to claim 9, wherein the atleast one protuberance includes a plurality of protuberances extendingacross the radial span dimension.
 13. The turbomachine according toclaim 9, wherein the at least one protuberance extends from about 5% ofthe radial span dimension to about 100% of the radial span dimension.14. The turbomachine according to claim 13, wherein the at least oneprotuberance extends from about 50% of the radial span dimension toabout 95% of the radial span dimension.
 15. The turbomachine accordingto claim 14, wherein the at least one protuberance extends from about50% of the radial span dimension to about 90% of the radial spandimension.
 16. The turbomachine according to claim 9, wherein theturbomachine airfoil comprises a turbine bucket.
 17. A method of forminga turbomachine airfoil comprising: forming a base portion and a bladeportion; and creating at least one protuberance on a pressure side ofthe blade portion, the at least one protuberance extending from about10% of an axial chord dimension to about 90% of the axial chorddimension of the blade portion.
 18. The method of claim 17, wherein theat least one protuberance includes forming a plurality of protuberanceson the one of the pressure side.
 19. The method of claim 18, whereinforming a plurality of protuberances on the pressure side includesforming a plurality of protuberances across one of the axial chorddimension and the radial span dimension.
 20. The method of claim 17,wherein the at least one protuberance includes forming the at least oneprotuberance between about 5% of a radial span dimension to about 100%of the radial span dimension.